According to the city's mayor, Walt Cobb, the deteriorating conditions Tuesday morning were obvious to anyone who stepped outside.

"You can't see much, let's put it that way. It's very smoky. The surrounding fires are bringing smoke in, so the visibility and the air quality is quite bad," Cobb told The Early Edition.

Most elderly residents and people with respiratory problems have already been evacuated from the city, he added. Everyone else remains on evacuation alert.

The entire city of Williams Lake was placed under an evacuation alert late Monday. (CBC)

Wildfire smoke pushes into Alberta

Special air quality statements related to the wildfires have been issued by Environment Canada for the entire southeast corner of B.C., from the Similkameen in the south to the Chilcotin and Prince George in the north, all the way east to the Alberta border.

"It's actually pushing all the way into Alberta," MacDonald said. "All that smoke is gradually pushing east and northeastwards into the Rockies."